Kelce's extension includes $13 million guaranteed. Add in a bonus as one of the league's top-five paid centers and his deal could reach a total value of $40.1 million, a person with knowledge of the deal told USA TODAY Sports. That person requested anonymity since the club has not released the details.

Kelce returned from a Week 2 knee injury in 2012 to help pave the way for league-leading rusher LeSean McCoy and Kelly's offense that set a franchise record by scoring 442 points for the 10-6 Eagles, who won the NFC East division in Kelly's first season.

His deal was the first extension completed for the first draft class (2011) under the new collective bargaining agreement.

"Jason is the epitome of the type of player we want around here, both on and off the field,'' Kelly said in a statement about the sixth-round selection. "He's tough, extremely intelligent and is a leader by his actions and by his words. His athleticism is something that really sticks out when you watch him play. There aren't many centers that can get down the field like he does.''

Cooper, who was eligible to hit free agency March 11, rebounded when some media members speculated that his career in Philadelphia might be finished after he was caught on video yelling a racial epithet at an African-American security guard during a summer Kenny Chesney concert.

After apologizing to his teammates and undergoing team-mandated sensitivity counseling, Cooper had a breakout season with 47 receptions for a career-best 835 yards with eight touchdowns. His 17.8 yards per reception ranked third best in the league.

"Riley is one of the toughest and hardest-working guys in our locker room,'' Kelly said. "We talk a lot about how players have to make the most of their opportunities. And he did just that last year.

"He used his size, strength and speed to make a lot of big plays for our team and I'm excited to watch him build upon his success.''